jimmydanny

Hi! Some of you have read my previous thread which I started a week ago or so, trying to bring some heads together for a brainstorm to get my idle working.

Well, I sat there with my timing light, and for once I checked my T1 as well as my L1. And, well... uhm, it didn't even ignite half the times it seemed.

So, I swapped to my new coil which I had conveniently placed in my trunk, as well as the stock plug wires in place of the Mazdatrix ones, as they have a bad rep on them.

A bit better, it was on the mark timing wise, without taking out the CAS and setting it on the spot down there, so something was correct for once.

Then I advanced the timing (counter-clockwise is advancing if I remember correctly just now) by just turning the CAS with the bolt in to the max.

BAM! Idle on 700-750 area, stable as hell!

But, when I revved it, it ran like a pack of fermented sausages. I mean, it was so much **** going through the exhaust, I got 9-10psi with the clutch in. That should not happen, and can not happen, unless it is something very very wrong.

So, my question is, what causes my idle to go lower, stabilize, but the engine to run like ****, and put so much exhaust out that it boosts to my set wastegate level in neutral? :O

No matter how bad this sounds, I feel like I am alot closer than where I was when my idle was going bouncy-bounce at 1500-2000 like one week ago.

AGreen

iTrader: (11)

1) Set the timing the proper way. Warm the engine up fully, jumper the initial set coupler, attach the inductive lead to the L1 wire and set the timing to the 5ATDC mark. Disconnect the initial set coupler jumper. Check that you have good clean spark plugs.

2) Get a voltmeter and check the green/red wire at the TPS. It should read 1.000 volts to ground when fully warm. If not, adjust the TPS to 1.000v.

3) Inspect for intake leaks. Anything between the Airflow Meter and the engine, to include the inlet duct, throttle body, manifold, everything. Surging idles are VERY commonly caused by vacuum or intake leaks. Use a can of brake cleaner or carburetor cleaner and shoot all around the intake and listen to the idle. If it smooths out, you've found it.

4) Now you need to pull the passenger's side carpet back and backprobe the ECU. Check pin 2I. That's the water thermosensor, as Mazda calls it. Most commonly known as the Engine Coolant Temperature sensor. It should read between 0.4v and 1.8v with the engine warm. Also check pin 2B. Check it with the engine running, and also engine off, but with the key on. Report readings.

We'll start here and see what happens.

jimmydanny

The thermosensor, doesn't that make other problems than just idle? Because except for this, it runs great when the idle is bouncy.

AGreen

iTrader: (11)

There are a few things you can check while you're down by the ECU, might as well rule it out. I had a hot start problem linked to faulty wiring to the thermosensor, others have had different issues. It all depends on how it fails. Just check it to cross it off the list.

jimmydanny

Will do when it stops raining shitbuckets here. Will take another session tomorrow with the TPS and ignition timing just to be sure, if there is no cars parked at the teachers parking at the school They got roof!

If I got time, I will take a look at the ECU as well, might sneak me into the school and print some pin-outs.

jimmydanny

One more question. The water thermosensor, isn't that the one that also sends a signal range to my gauge cluster? If that was defective, shouldn't that one not work then? It works as it should on my car atleast...

Just pondering.

clokker

iTrader: (2)

No, the gauge has its own sending unit.

misterstyx69

iTrader: (142)

Water thermo is on the back side the water pump
Water Temp is on the side of the engine.

jimmydanny

Ah ofc, I remember now! I will take a look into it later today if I get time! Got a new computer in parts, distractions everywhere!